检索结果-南通市图书馆

Charging and self-discharging process of a quantum battery in composite environments

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2023年第3期18卷 203-214页

作者： Kai Xu Han-Jie Zhu Hao Zhu guo-feng zhang Wu-Ming Liu School of Science Tianjin University of TechnologyTianjin 300384China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physics Beihang UniversityBeijing 100191China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China

How to improve charging processes and suppress self-discharging processes has always been one of the key issues to achieve quantum batteries with high performance.Although a quantum battery is inevitably influenced by composite environments,this situation is still little understood,particularly regarding the influence of the memory effect of the composite environments and the coupling between composite environments.In this work,we investigate the effects of the composite environments,composed of two identical parts each containing a single cavity mode decaying to a reservoir,on the charging and self-discharging processes of a quantum battery.We show that increasing the two-mode coupling can effectively enhance the charging performance(i.e.,the stored energy,the charging power,ergotropy)and restrain the self-discharging process(i.e.,suppressing the process of dissipating the energy).However,different from the effect of two-mode coupling,we reveal that the memory effect of the reservoir in this composite environment is unfavorable to the charging process of the quantum battery,which is in sharp contrast to previous studies where the memory effect can significantly improve the charging performance of a quantum battery.Our results may benefit to the realization of quantum batteries with high performance under the actual complex environmental noise.

关键词： quantum battery quantum device

May 2022 Greedy Kaczmarz Algorithm Using Optimal Intermediate Projection Technique for Coherent Linear Systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Numerical Mathematics(Theory,Methods and Applications) 2022年第2期15卷 464-483页

作者： Fang Geng Li-Xiao Duan guo-feng zhang School of Mathematics and Statistics Lanzhou UniversityLanzhou 730000China

The Kaczmarz algorithm is a common iterative method for solving linear systems.As an effective variant of Kaczmarz algorithm,the greedy Kaczmarz algorithm utilizes the greedy selection strategy.The two-subspace projection method performs an optimal intermediate projection in each iteration.In this paper,we introduce a new greedy Kaczmarz method,which give full play to the advantages of the two improved Kaczmarz algorithms,so that the generated iterative sequence can exponentially converge to the optimal solution.The theoretical analysis reveals that our algorithm has a smaller convergence factor than the greedy Kaczmarz method.Experimental results confirm that our new algorithm is more effective than the greedy Kaczmarz method for coherent systems and the two-subspace projection method for appropriate scale systems.

关键词： Kaczmarz algorithm two-subspace greedy methods linear systems

Study on the influence of curcumin on chemosensitivity of nephroblastoma cells

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2016年第8期9卷 779-782页

作者： Xiao-Yong Li Yuan-Yuan feng Wei Dan Deng Pan guo-feng zhang Xian-Liang Wang Guang-Jun Hou Department of Pediatric Surgery Children's Hospital of Zhengzhou Department of Paediatrics Children's Hospital of Zhengzhou Department of Paediatrics Maternal and Child Health Hospital of Tonglu County

Objective:To study the influence of curcumin on chemosensitivity of nephroblastoma cells.Methods:Human nephroblastoma cells line SK-NEP-1 was transplanted to the nude mice subcutaneously to establish the implantation tumor model of human nephroblastoma cells.A total of 30 tumor-bearing mice were divided into three groups of ten randomly.The routine chemotherapy group was given vincristine(0.05 mg/mL·0.2 mL/d) and actinomycin D(15 ng/mL·0.2 mL/d) combined chemotherapy regime.The curcumin chemotherapy group was given the same combined chemotherapy regimens and curcumin(30 mg/kg/d) by intraperitoneal injection.The control group was given normal saline(NS) of the same volume by intraperitoneal injection.Continuous administration would be kept for 4 weeks and 3 days a week.The volumetric changes of every group were recorded.The serum of every group in different time was collected and the VEGF content was detected by ELISA.All mice were cercrificed and the tumor tissues were stripped and weighed after 4 weeks’ treatment.The tumor inhibition rate was calculated.The cell proliferation activity and apoptosis rate were detected by MTT and flow cytometry method.All data were statistically analyzed by SPSS 19.0.Results:The tumor volume,serum VEGF content,tumor inhibition rate,cell proliferation activity and apoptosis rate of routine chemotherapy group and curcumin chemotherapy group had significant differences comparing with the control group(P<0.05) after 4-week’s treatment.The cancer growth of curcumin chemotherapy group was obviously decreased and even tended to shrink comparing with routine chemotherapy group(χ2=15.732,P=0.007).The cell proliferation activity was significantly reduced and the apoptosis rate was significantly higher,(χ~2=9.427,P=0.012)which showing the effect of chemotherapy was enhanced.Conclusions:The chemosensitivity of nephroblastoma cells could be improved by curcumin,then the effect of preoperative adjuvant chemotherapy scheme would be enhanced,the growth of nephroblastoma cells would be inhibited a

关键词： Nephroblastoma Transplanted tumor model Curcumin Chemosensitivity Vincristine

Synthesis of Fluorene-Bridged Arylene Vinylene Fluorophores： Effects of End-Capping Groups on the Optical Properties, Aggregation Induced Emission

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2015年第8期33卷 939-947页

作者： guo-feng zhang Tao Chen Ze-Qiang Chen Matthew P. Aldred Xianggao Meng Ming-Qiang Zhu Wuhan National Laboratory for Optoelectronics School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan Hubei 430074 China Department of Chemistry Durham University South Road Durham DH1 3LE UK Key Laboratory of Pesticide and Chemical Biology of Ministry of Education College of Chemistry Central China Normal University Wuhan Hubei 430079 China

We have synthesized a series of fluorene-based fluorophores, in which a central fluorene core has been modified with different peripheral arylene vinylene substituents that are able to activate aggregation-induced emission （AIE） characteristics. 9,9-Dioctylfluorene doubly end-capped at the 2,7-positions with triphenylethene groups, such as 4-（2,2-diphenylvinyl）phenyl （F1-（2,2）-HTPE） and 4-（1,2-dipbenylvinyl）phenyl （F1-（1,2）-HTPE） were synthesized and compared to the tetraphenylethene analogue （F1-TPE）. Both FI-（2,2）-HTPE and F1-（1,2）-HTPE glow with a deep blue fluorescence in THF solution with emission maxima （λem） of 426 and 403 nm, respectively. The λem slightly red-shifts in the solid-state to 458 nm for F 1-（2,2）-HTPE and 437 nm for F 1-（1,2）-HTPE. The fluorescence quantum yields （ΦF） of F1-（2,2）-HTPE （ΦF=35.1%） and FI-（1,2）-HTPE （ΦF=26.2%） were found to be higher in solution compared to the near quenching of F 1-TPE （ΦF = 0.1%）. Consequently, this results in weaker AIE-stability of F1-（2,2）-HTPE （αAIE= 1.5） and F1-（1,2）-HTPE （αAIE=1.9） compared to F1-TPE （αAIE=125）, suggesting that four phenyl groups are necessary for efficient AIE-activity of these fluorene bridged arylene vinylene type materials In addition, decreasing the steric hindrance around the arylene vinylene moiety by removal of a phenyl ring is an- other method to decrease the AIE characteristics, in a similar manner to the commonly known ＂phenyl-locking＂. Non-polar triphenylethenes are poorer AlE materials than their tetraphenylethene analogues. Replacing the hydro- gen atom of F1-（2,2）-HTPE with a cyano group affords fluorene end-capped with 2,3,3-triphenylacrylonitrile （F1-TPAN）, which boosts the AIE-effect to αAIE=90.5 and red-shifts the solid-state emission （λem=528 nm） with near quenching in THF solution （ΦF= 0.12%）. X-ray crystallographic analysis of F1-TPAN indicates that the intro- duction of cyano groups can not only diminish the intramolecular steric hindrance in comparison of F1-TPE, but also improve the molecular cohesion ability via

关键词： aggregation-induced emission fluorene triphenylethene tetraphenylethene 2,3,3-triphenylacrylonitrile

Modification of single molecule fluorescence using external fields

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of physics 2017年第5期12卷 11-25页

作者： Rui-Yun Chen guo-feng zhang Cheng-Bin Qin Yan Gao Lian-Tuan Xiao Suo-Tang Jia State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser Spectroscopy Shanxi University Taiyuan 030006 China Collaborative Innovation Center of Extreme Optics S hanxi University Taiyuan 030006 China

控制并且操作单个 fluorophores 的荧光具有对为它在改进分子的 photonics 和分子的电子学的表演的潜在的使用的最近的年的大兴趣，例如在基于单个分子的器官的轻射出的设备，单个光子来源，器官的地效果晶体管，和探针或传感器。这评... 详细信息

控制并且操作单个 fluorophores 的荧光具有对为它在改进分子的 photonics 和分子的电子学的表演的潜在的使用的最近的年的大兴趣，例如在基于单个分子的器官的轻射出的设备，单个光子来源，器官的地效果晶体管，和探针或传感器。这评论显示出单个器官的分子的荧光排放怎么能用金属性的 nanostructures 和 electric-field-induced 电子转移的本地电磁的领域被修改。荧光开关的 Electric-field-induced 荧光调整，磁滞现象，和成就详细被讨论。

关键词：单分子荧光有机电致发光器件场效应晶体管单分子传感器电场诱导分子电子学潜在用途单光子源

PHOTOSWITCHABLE NANOFLUOROPHORES FOR INNOVATIVE BIOIMAGING

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Innovative Optical Health Sciences 2011年第4期4卷 395-408页

作者： MING-QIANG ZHU guo-feng zhang CHONG LI YA-JING LI MATTHEW PALDRED ALEXANDER D.Q.LI Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 China Department of Chemistry Washington State University PullmanWA 99164USA

Photosensitive fluorescent probes have become powerful tools in chemical biology and molecular biophysics,which are used to investigate cellular processes with high temporal and spatial resolution.Accordingly,photosensitive fluorescent probes,including photoactivatable,photoconvertible,and photoswitchable fluorophores,have been extensively developed during the past decade.The photoswitchable fluorophores have received much attention because they highlight cellular events clearly.This minireview summarizes recent advances of using reversibly photoswitchable fluorophores and their applications in innovative bioimaging.Photoswitchable fluorophores include photoswitchable fluorescent proteins,photoswitchable fluorescent organic molecules(dyes),and photoswitchable fluorescent nanoparticles.Several strategies have been developed to synthesize photoswitchable fluorophores,including engineering combination proteins,chemical synthesis,polymerization,and self-assembly.Here we concentrate on polymer nanoparticles with optically switchable emission properties:either fluorescence on/offor dualalternating-color fluorescence photoswitching.The essential mechanisms of fluorescence photoswitching enable different types of photoswitchable fluorophores to change emission intensity or wavelength(color)and thus validating the basis of the fluorescence on/offor dual-color photoswitching design.Generally the possible applications of any fluorophores are to label biological targets,followed by specific imaging.The newly developed photoswitchable fluorophores enable super-resolution fluorescence imaging because of their photosensitive emission.Finally,we summarize the important area regarding future research and development on photoswitchable fluorescent nanoparticles.

关键词： Fluorescent molecular switches polymer nanoparticles two-photon two-photon imaging spiropyran

Giant enhancement of photoluminescence emission in monolayer WS_(2)by femtosecond laser irradiation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of physics 2021年第1期16卷 143-150页

作者： Cheng-Bing Qin Xi-Long Liang Shuang-Ping Han guo-feng zhang Rui-Yun Chen Jian-Yong Hu Lian-Tuan Xiao Suo-Tang Jia State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser SpectroscopyShanxi UniversityTaiyuan 030006China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Monolayer transition metal dichalcogenides have emerged as promising mat erials for opt oelectTonic and nanophotonic devices.However,the low photoluminescence(PL)quantum yield(QY)hinders their various potential applications.Here we engineer and enhance the PL intensity of monolayer WS_(2)by femtosecond laser irradiation.More than two orders of magnitude enhancement of PL intensity as compared to the as-prepared sample is determined.Furthermore,the engineering time is shortened by three orders of magnitude as compared to the improvement of PL intensity by continuous-wave laser irradiation.Based on the evolution of PL spectra,we attribute the giant PL enhancement to the conversion from trion emission to exciton,as well as the improvement of the QY when exciton and trion are localized to the new-formed defects.We have created microstructures on the monolayer WS_(2)based on the enhancement of PL intensity,where the engineered structures can be stably stored for more than three years.This flexible approach with the feature of excellent long-term storage stability is promising for applications in information storage,display technology,and opto electronic devices.

关键词： monolayers WS_(2) giant enhancement photoluminescence femtosecond laser irradiation micropatterning exciton trion quantum yield

Influence of surface charges on the emission polarization properties of single CdSe/CdS dot-in-rods

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of physics 2019年第6期14卷 73-82页

作者： guo-feng zhang Chang-Gang Yang Yong Ge Yong-Gang Peng Rui-Yun Chen Cheng-Bing Qin Yan Gao Lei zhang Hai-Zheng Zhong Yu-Jun Zheng Lian-Tuan Xiao Suo-Tang Jia State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser Spectroscopyand Collaborative Innovation Center of Extreme OpticsShanxi UniversityTaiyuan 030006China Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China School of Physics Shandong UniversityJinan 250100China

We report an experimental investigation of the influence of surface charges on the emission polarization properties of single CdSe/CdS dot-in-rods(DRs),which is important for their polarization-based practical applications.By covering the single DRs with N-type semiconductor indium tin oxide(ITO)nanoparticles,the surface of single DRs is charged by ITO through interracial electron transfer.This is confirmed by the experimental observations of the reduced photoluminescence intensities and lifetimes as well as the suppressing blinking.It is found that the full width at half maximum of histogram of polarization degrees of the single DRs is broadened from 0.24(on glass)to 0.41(in ITO).In order to explain the exprimental results,the band-edge exciton fine structure of single DRs is calculated by taking into account the sample parameters,the emission polarization,and the surface charges.The calculation results show that the level ordering of the emitting states determines the polarization degrees tending to increase or decrease under the influence of surface electrons.The surface electrons can induce an increase in the spacing between the emitting levels to change the populations and thus change the polarization degrees.In addition,different numbers of surface electrons may randomly distribute on the long CdSe/CdS rods,leading to the heterogeneous influences on the single DRs causing the broadening of polarization degrees also.

关键词： single CdSe/CdS dot-in-rods polarization properties surface charges band-edge exciton fine structure

Linear dipole behavior of single quantum dots encased in metal oxide semiconductor nanoparticles films

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of physics 2019年第2期14卷 97-104页

作者： guo-feng zhang Yong-Gang Peng Hai-Qing Xie Bin Li Zhi-Jie Li Chang-Gang Yang Wen-Li guo Cheng-Bing Qin Rui-Yun Chen Yan Gao Yu-Jun Zheng Lian-Tuan Xiao Suo-Tang Jia State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser SpectroscopyShanxi UniversityTaiyuan 030006China School of Physics Shandong UniversityJinan 250100China Department of Physics Taiyuan Normal UniversityJinzhong 030619China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Understanding of charge/energy exchange processes and interfacial interactions that occur between quantum dots (QDs) and the metal oxides is of critical importance to these QD-based optoelectronic devices. This work reports on linear dipole behavior of single near-infrared emitting CdSeTe/ZnS core/shell QDs which are encased in indium tin oxide (ITO) semiconductor lianoparticles films. A strong polarization anisotropy in photohiminescence emission is observed by defocused wide-field imaging and polarization measuremen11echniques, and the average polarization degree is up to 0.45. A possible mechanism for the observation is presented in which the electrons, locating at single QD surface from ITO by electron transfer due to the equilibration of the Fermi levels, result in a significant Stark distortion of the QD electron/hole wavefunctions. The Stark distortion results in the linear polarization property of the single QDs. The investigation of linear dipole behavior for single QDs encased in ITO films would be helpful for further improving QD-based device performance.

关键词： single quantum dots linear dipole behavior electron transfer polarization property metal oxide nanoparticles